Department of Dermatology, Cardinal Tien Hospital, Hsin Tien, New Taipei, Taiwan.
J Dermatolog Treat. 2012 Oct;23(5):333-8. doi: 10.3109/09546634.2011.560929. Epub 2011 Jul 14.
Q-switched laser treatment for pigment disorders commonly leads to postinflammatory hyperpigmentation (PIH) in Asians.
To evaluate the effect of spot size and fluence on Q-switched alexandrite laser (QSAL) treatment for pigmentation in Asians.
Ten patients with freckles, 18 with lentigines, and 8 with acquired bilateral nevus of Ota-like macules (ABNOM) received 1 session of QSAL treatment for a 3-mm spot on one cheek and a 4-mm spot on the other cheek. The lowest fluences to achieve a visible biologic effect were chosen.
The patients with freckles experienced the highest improvement rate (83-84%), followed by those with lentigines (52%) and ABNOM (35%). Similar efficacy was observed for both cheeks (p > 0.05). PIH developed in 10% (1/10), 44% (8/18), and 75% (6/8) of the patients with freckles, lentigines, and ABNOM, respectively. The severity of PIH was lower in the 4-mm spot with a lower fluence than in the 3-mm spot with a higher fluence in patients with lentigines (p = 0.03), but not in those with freckles or ABNOM.
Using a larger spot to achieve the same biologic effect at a lower fluence is associated with equal efficacy and less-severe PIH in patients with lentigines.
Q 开关激光治疗色素疾病在亚洲人中常导致炎症后色素沉着（PIH）。
评估光斑大小和能量密度对 Q 开关紫翠宝石激光（QSAL）治疗亚洲人色素沉着的影响。
10 例雀斑患者、18 例色素痣患者和 8 例获得性双侧太田痣样斑（ABNOM）患者，在一侧脸颊接受 3mm 光斑和另一侧脸颊接受 4mm 光斑的 QSAL 治疗，选择达到可见生物学效应的最低能量密度。
雀斑患者的改善率最高（83-84%），其次是色素痣患者（52%）和 ABNOM 患者（35%）。两侧脸颊的疗效相似（p>0.05）。雀斑、色素痣和 ABNOM 患者中分别有 10%（1/10）、44%（8/18）和 75%（6/8）出现 PIH。在色素痣患者中，较低能量密度的 4mm 光斑比较高能量密度的 3mm 光斑引起的 PIH 严重程度更低（p=0.03），但在雀斑或 ABNOM 患者中并非如此。
对于色素痣患者，使用较大光斑以较低能量密度达到相同的生物学效应与同等疗效和较轻的 PIH 相关。
